1. Field of the Invention
This invention relates to the field of separation of pressurized gases having different boiling points, and more particularly, the separation or partial separation of gaseous ammonia and water vapor from a pressurized gaseous aqueous ammonia stream.
2. Description of the Prior Art
Various processes are in use wherein an aqueous ammonia vapor under pressure is produced, such as the stripper column in a process such as taught in U.S. Pat. Nos. 3,024,090; 3,054,726; 3,186,795; and 3,985,863, each incorporated herein by reference. This vapor is usually either condensed and fed to an ammonia-distillation facility to recover the ammonia or fed to a unit to destroy the ammonia catalytically or by combustion. These methods are generally very expensive due to the large equipment needed. If there are large quantities of ammonia produced, then the costly large equipment for recovery of the ammonia can be justified. However, where the quantities of ammonia are relatively small, it becomes impractical to recover the ammonia. Destruction of the ammonia catalytically is relatively expensive. The aqueous ammonia is often at an ammonia concentration of between about 5 and about 40 percent by volume. At these concentrations, it is not even possible to combust the gaseous stream without adding additional expensive fuel. The combustion equipment required for such incineration tends to be large and expensive.